Hong Kong’s subway system is maintained by 10,000 people who conduct 2,600 jobs across the extensive and well-run system. The trains are on time 99.9 percent of the time, according to NewScientist, and the whole thing is managed by an artificial intelligence.

The AI uses a simulated model of the subway and a genetic algorithm to decide on a schedule for needed maintenance, inspections and other jobs needed to comply with governmental regulations. All decisions are approved by a human, but the AI’s work makes the whole system run far more efficiently than if a person were doing all the work, according to Hong Kong officials.